Feature: backend endpoints for sponsored transactions

README.md

@@ -3,8 +3,12 @@
 ZKLogin implementation using Mysten Labs' Enoki service for user's salt management and prover service.
 
 This template includes:
-* ZKLogin using google
-* Transferring SUI to wallet address
-* Minting a sample NFT with and without using sponsored transaction.
+
+- ZKLogin using google
+- Transferring SUI to wallet address
+- Minting a sample NFT with and without using sponsored transaction.
+- Support for sponsored transactions using private API from enoki, using a backend service.
 
 Note: This implementation of sponsored transactions bypasses the current limitation of Enoki's service by supporting them through self-owned wallet.
+
+Node versions: v18 and above for the frontend, v20 and above for the backend.

backend/.env.example

@@ -0,0 +1,2 @@
+PORT=
+ENOKI_PRIVATE_API_KEY=

backend/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "sui-zklogin-enoki",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "type": "module",
+  "scripts": {
+    "start": "nodemon src/index.js"
+  },
+  "author": "Saajan Duwal",
+  "license": "ISC",
+  "dependencies": {
+    "@mysten/enoki": "^0.4.4",
+    "cors": "^2.8.5",
+    "dotenv": "^16.4.5",
+    "express": "^4.21.0",
+    "nodemon": "^3.1.7"
+  }
+}

backend/src/index.js

@@ -0,0 +1,78 @@
+import "dotenv/config";
+import express from "express";
+import cors from "cors";
+
+const app = express();
+const port = process.env.PORT || 8000;
+
+import { executeTx, sponsorTx } from "./services/sponsoredServices.js";
+
+app.use(cors());
+app.use(express.json());
+
+app.post("/api/v1/sponsor", async (req, res) => {
+  const { network, sender, txBytes, allowedAddresses, allowedMoveCallTargets } =
+    req.body;
+
+  if (!network || !sender || !txBytes) {
+    return res.status(400).json({
+      error: "Missing necessary parameters.",
+    });
+  }
+
+  try {
+    const sponsoredTxRes = await sponsorTx({
+      network,
+      sender,
+      transactionKindBytes: txBytes,
+      allowedAddresses,
+      allowedMoveCallTargets,
+    });
+
+    return res.status(200).json({
+      bytes: sponsoredTxRes.bytes,
+      digest: sponsoredTxRes.digest,
+    });
+  } catch (error) {
+    console.error(error);
+    return res
+      .status(500)
+      .json({ error: "An error occurred while processing the transaction." });
+  }
+});
+
+app.post("/api/v1/execute", async (req, res) => {
+  const { digest, signature } = req.body;
+
+  if (!digest || !signature) {
+    return res.status(400).json({
+      error: "Missing necessary parameters.",
+    });
+  }
+
+  try {
+    const sponsoredTxRes = await executeTx({
+      digest,
+      signature,
+    });
+
+    if (!sponsoredTxRes.digest) {
+      return res.status(400).json({
+        error: "Failed to get digest for the transaction.",
+      });
+    }
+
+    return res.status(200).json({
+      digest: sponsoredTxRes.digest,
+    });
+  } catch (error) {
+    console.error(error);
+    return res
+      .status(500)
+      .json({ error: "An error occurred while processing the transaction." });
+  }
+});
+
+app.listen(port, () => {
+  console.log(`Server running at http://localhost:${port}`);
+});

backend/src/services/sponsoredServices.js

@@ -0,0 +1,39 @@
+import { EnokiClient } from "@mysten/enoki";
+
+const ENOKI_PRIVATE_API_KEY = process.env.ENOKI_PRIVATE_API_KEY;
+
+export const sponsorTx = async (txData) => {
+  try {
+    const enokiClient = new EnokiClient({
+      apiKey: ENOKI_PRIVATE_API_KEY,
+    });
+
+    const sponsoredTxRes = await enokiClient.createSponsoredTransaction({
+      network: txData.network || "mainnet",
+      transactionKindBytes: txData.transactionKindBytes,
+      sender: txData.sender || "",
+      allowedAddresses: txData.allowedAddresses,
+      allowedMoveCallTargets: txData.allowedMoveCallTargets,
+    });
+    console.log("sponsoredTxRes", sponsoredTxRes);
+    return sponsoredTxRes;
+  } catch (error) {
+    throw error;
+  }
+};
+
+export const executeTx = async (txData) => {
+  try {
+    const enokiClient = new EnokiClient({
+      apiKey: ENOKI_PRIVATE_API_KEY,
+    });
+    const executeTxRes = await enokiClient.executeSponsoredTransaction({
+      digest: txData.digest,
+      signature: txData.signature,
+    });
+    console.log("executeTxRes", executeTxRes);
+    return executeTxRes;
+  } catch (error) {
+    throw error;
+  }
+};